Whole Course Flashcards
Made From Notes at: http://www.duncanrig.s-lanark.sch.uk/wp-content/uploads/National-5-Full-Course-Glossary.pdf
Mitochondria
The site of aerobic respiration
Chloroplasts
The site of photosynthesis in a plant cell
cell membrane
Controls the entry and exit of materials
vacuole
A large, cell sap-filled space in plant cells
nucleus
Contains DNA and controls all cell activities
cytoplasm
Site of chemical reactions
ribosomes
The site of protein synthesis
plasmids
Small circular pieces of DNA in bacterial cells
Cell walls
Provides cell with shape and support. Made of cellulose in plant cells and different materials in bacteria and
fungi
The cell membrane consists of
phospholipids and proteins
The cell membrane is
selectively permeable
passive transport is
Down the concentration gradient and does not require energy.
diffusion in cells is
The movement of molecules down a concentration gradient
Osmosis is
The movement of water molecules from a high water concentration to a low water concentration through a
selectively permeable membrane
Animal cells in low water concentration will
Shrink
Animal cells in high water concentration will
Burst
Plant cells in low water concentration will
Become plasmolysed- vacuole shrinks and cytoplasm pulls away from cell wall
Plant cells in high water concentration will become
Become turgid- swollen
Active transport
Requires energy for membrane proteins to move molecules and ions against the concentration gradient
DNA carries
The genetic information for making proteins
A DNA molecules is
A double-stranded helix
A gene is
A section of DNA which codes for a particular protein
DNA double strands are held together by
Complementary base pairs
The four bases in the genetic code are
Adenine, cytosine, guanine and thymine (A,T,C,G)
The base sequence determines
The amino acid sequence in a protein
mRNA carries
A complementary copy of the code from the DNA, in the nucleus, to a ribosome
The ribosome is where
The protein is assembled from amino acids
The sequence of amino acids
Controls the shape and function of proteins
Structural proteins
Hold tissues together e.g. collagen
Hormones
Are chemical messengers which carry a message from a gland to a receptor via the blood
Antibodies
Are proteins, made by white blood cells, which bind to invading microbes
Receptors
Receive a signal from the environment and pass it on to a sensory neuron OR bind to a hormone and tell the cell
what to do.
Enzymes
Are biological catalysts and are made by all cells
Biological catalysts
Speed up biochemical reactions in cells and remain unchanged in the process
Enzyme specificity
One enzyme will only catalyse one reaction
Active site
The part of the enzyme that the substrate attaches to
and is a complementary shape to it
Substrate
The reactant(s) in a reaction, and is specific to an enzyme
Product
The molecule made by an enzyme-controlled reaction
Denatured
When the active site permanently changes shape and affects the rate of the enzyme reaction
Optimum conditions
Are the temperature and pH which the enzymes work best at
Finished the sentences on the process of genetic engineering.
- Identify the section of DNA that has
- Then you need to
- And
- Then insert
- Then insert
Then the transformed cells need to
- Identify the section of DNA that has the gene required, on the source chromosome
- Then you need to extract (cut out) the gene
- And extract the plasmid from the vector/bacterial cell
- Then insert the cut out gene into a bacterial plasmid
- Then insert the plasmid into the host cell (bacteria)
Then the transformed cells need to grow and divide to produce a GM organism
Enzymes are needed to
Cut the DNA to extract the gene, cut the plasmid open and seal the gene into the plasmid
Respiration is defined as
A series of enzyme-controlled reactions which release the chemical energy stored in glucose
The energy released from respiration is used to make
ATP from ADP and Pi
The chemical energy in ATP can be released by
Breaking it down into ADP and Pi
The released energy from respiration can be used for
muscle cell contraction, cell division, protein synthesis, transmission of nerve impulses
Stage one of respiration breaks one molecule of glucose down into
2 molecules of pyruvate and releases enough energy to make 2 ATP molecules
Stage 2 of respiration with oxygen (aerobic respiration) breaks pyruvate down into
Carbon dioxide and water and yields 36 ATP molecules
Stage 2 of respiration without oxygen is called
Fermentation and yields 0 ATP molecules
The end product of fermentation in animal cells is
Lactate
The end products of fermentation in plant and yeast cells are
Ethanol + carbon dioxide
Total ATP yield of aerobic respiration
38 ATP molecules
Total ATP yield of fermentation
2 ATP molecules (only those produced in stage 1)
Respiration begins in
The cytoplasm
Fermentation is completed in
The cytoplasm
Aerobic respiration is completed in
The mitochondria
Respirometers
Measure the rate of respiration
Mitosis is
Normal cell division and provides new cells for growth and repair of damaged cells and maintains the diploid
chromosome complement
Chromatids are
Individual strands of a duplicated chromosome (joined together at centromere)
The equator
Is the middle of the cell where the chromosomes (pairs of chromatids) line up
Spindle fibres are
Where chromosomes attach to by the centromere; they contract to pull the chromatids apart to the poles
Stem cells are
Unspecialised cells which can divide in order to self- renew or differentiate (specialise) to become specialised cells
Stem cells are normally involved in
Growth and repair
Specialisation leads to the formation of
A variety of cells, tissues and organs
Groups of organs working together to perform a particular function is called an
Organ system
The hierarchy of organisation of living organisms is
Cells-tissues-organs-organ systems-organism
The central nervous system (CNS) consists of
The brain and the spinal cord
The brain contains
The cerebrum, cerebellum and medulla
The cerebrum controls
Conscious thought, intelligence, language
The cerebellum controls
Balance and co-ordination
The medulla controls
Unconscious control of body temp, heart and breathing rate, etc.
Neuron types are
Sensory, Inter and motor
Reflex actions are
Involuntary protective actions
The reflex arc is
Receptor – sensory neuron – relay neuron – motor neuron – muscle
Receptors
Detect stimuli / sensory information
Electrical impulses
Carry messages along neurons
Synapses
Gaps between neurons that the message has to cross via chemical messenge
Hormones are
Chemical messengers produced by endocrine glands which carry messages in the blood stream to target
tissues
Target tissues have cells with
Receptor proteins that are complementary to a specific hormone, so only that tissue will be affected by
that hormone
Blood glucose levels need to be
Controlled within safe limits (not too high and not too low)
Insulin is released when
The blood sugar rises above normal
Insulin causes
Liver cells to store excess glucose as glycogen returning blood glucose levels to normal
Glucagon is released when
The blood sugar falls lower than normal
Glucagon causes
Liver cells to release glucose into the blood returning blood glucose levels to normal
The pancreas
Is the endocrine gland which produces insulin and glucagon
All body cells, except gametes, are
Diploid
Gametes are
Haploid sex cells
Diploid means
The normal number of chromosomes in a cell. In humans this is 23 pairs (46).
Haploid means
Half the normal number of chromosomes in a cell. In humans this is 23.
Gametes have
Only one of each pair of chromosomes normally present in a diploid cell
Male gametes are made in
Testes (animals)/ anthers (plants)
Male gametes are called
Sperm (animals) / pollen (plants)
Female gametes are made in
Ovaries (animals)/ ovaries (Plants)
Female gametes are called
Eggs (animals) / ovules (plants)
Fertilisation is
The fusion of two haploid gametes to forma diploid zygote which undergoes many cell divisions to form an
embryo
Discrete variation (single gene inheritance)
Discontinuous, where the values do not occur in a range and fall into distinct groups (usually descriptions
e.g. colour)
Continuous variation (polygenic inheritance)
Where there is a range of values on a scale e.g. height
Polygenic characteristics
Caused by many genes working together. They show continuous variation and very common in phenotypes.
Phenotype
The visible physical characteristic you see as a result of a gene
Gene
A section of DNA which codes for a protein (characteristic)
Alleles
Different forms of a gene which control one characteristic
Genotype
The pair of alleles a person has which control one characteristic, e.g. AA, aa or Aa
Dominant
An allele which is always seen in the phenotype if it is present (in the genotype)
Recessive
An allele which is only seen in the phenotype if there is no dominant allele present
Homozygous
When a genotype has two alleles exactly the same, e.g. AA or aa
Heterozygous
When a genotype has alleles which are different from each other e.g. Aa
P1
F1 (first filial generation) F2 (second filial generation)
P1 -The genotypes of the parents in a cross
F1 (first filial generation) -The genotypes of the offspring from a cross
F2 (second filial generation)-The genotypes of the offspring resulting if two of the original F1 offspring were crossed
Predicted ratios are not always achieved
Because fertilisation is a random process or sample size is too small
Plant organs are
Roots, leaves and stems
Plants need water for
Transporting materials and for photosynthesis
Leaf cells, from top to bottom are
Upper epidermis, palisade mesophyll, spongy mesophyll, vein (consisting of xylem and phloem),
lower epidermis, guard cells, (stomata)
Root hair cells have a
Large surface area to increase absorption of water from the soil
Xylem vessels are
Dead and contain spirals of lignin for support
Xylem vessels transport
Water and minerals up the stem
The evaporation of water through leaves is called
Transpiration
Guard cells control
The opening and closing of stomata (turgid/swollen guard cells= open stomata)
The epidermis
Covers the upper and lower surfaces of a leaf transparent to let light through to photosynthetic layers
Phloem transports sugar and is made of
Living cells consisting of cytoplasmic strands and porous end plates between cells that allow sugar to move from
cell to cell. Companion cells provide energy for sieve tubes
In mammals, the substances transported by the blood are
Nutrients (glucose and amino acids), oxygen and carbon dioxide
In mammals, blood contains
Plasma, red blood cells and white blood cells
Red blood cells are specialised to transport oxygen by
Being biconcave in shape to increase surface area for absorption/diffusion of oxygen
Having no nucleus so more space for haemoglobin
Containing haemoglobin which bind to oxygen to transport it
When oxygen binds to haemoglobin in red blood cells it is called
oxyhaemoglobin
White blood cells are part of
The immune system and are involved in destroying pathogens (foreign organisms)
White blood cells called Lymphocytes produce
Antibodies which destroy pathogens
Antibodies are
Specific to a particular pathogen
The heart has four chambers.
The top two are:
The bottom two are:
The top two are: Right and left atria
The bottom two are: Right and left ventricles
White blood cells called phagocytes carry out
Phagocytosis to engulf and destroy pathogens
The heart contains valves which are found
Between the atria and ventricles and between the ventricles and arteries
Valves
Prevent the backflow of blood
Veins carry blood
Back to the heart, into the atria
The pathway of blood through the heart, lungs and body is; beginning with the lungs:
Lungs (oxygenated) – pulmonary vein – left atrium – valve – left ventricle – valve – aorta – body cells
(deoxygenated) – vena cava – right atrium – valve – right ventricle – valve – pulmonary artery – lungs
Arteries carry blood under
High pressure
The structures of arteries which help them to do this are
1 thick muscular walls
2 narrow central channel (lumen)
Veins carry blood under
Low pressure
The structures of veins which help them to do this are
1 Thinner walls
2 wide central channel (lumen)
3 valves to prevent backflow of blood
Capillaries are found in
Organs and tissues as networks
Capillaries are where
Exchange of materials happens, e.g. glucose, carbon dioxide, oxygen, urea, by diffusion
Capillaries are adapted for this by
1 having a large surface area for diffusion
2 having very thin walls – one cell thick
Oxygen and nutrients from food must be absorbed into the bloodstream and delivered to cells for
respiration
Waste materials must be removed from cells into the bloodstream. Waste materials include
Carbon dioxide
Surfaced involved in the absorption of materials have these features in common
Large surface area
Thin walls
Extensive blood supply
Large surface area, Thin walls,Extensive blood supply during absorption
Increase efficiency of absorption
Tissues contain capillary networks to allow
Exchange of materials at cellular level
Gas exchange in the lungs happens in the
Alveoli
In alveoli, the direction of gas movement is
Oxygen in, carbon dioxide out
The gases are exchanged from
The blood capillaries surrounding the alveoli
alveoli are adapted for diffusion by
1 having a large surface area (there are many of them) 2 having a good blood supply (covered by capillary
networks)
3 having thin walls (one cell thick) for more efficient diffusion
The small intestine is where
Absorption of food happens
The small intestine contains many millions of
Villi
Villi are
- thin walled
- have a large surface area (there are many of them)
- have a good blood supply to aid absorption- each villus contains a network of capillaries)
Water soluble food products are
Glucose and amino acids
They are absorbed into the
Blood capillary
Fat soluble food products are
Fatty acids and glycerol
They are absorbed into
The central lacteal
Biodiversity is
All the organisms of one species in a habitat
Population
All the organisms of one species in a habitat
Community
All the living organisms living in a habitat
An ecosystem is
All the organisms (community) living in a habitat and the non-living components with which the organisms interact (the abiotic factors)
Consumer
Organisms which rely on eating other organisms for food
Carnivore
A meat-eater
Herbivore
A plant-eater
Omnivore
An organism which eats both plants and animals
Food chain
Shows the transfer of energy between organisms
Between levels in a food chain, 90% energy is
Lost as heat, movement or undigested materials
A niche is
The role that an organism plays within a community
A niche describes:
The resources the organism uses in an ecosystem (light, temperature, nutrient availability)
The interactions and organism has in the community (competition, parasitism, predation)
Competition between organisms in ecosystems occurs when
Resources are in short supply
Interspecific competition is
between members of different species competing for one or a few similar resources the require
Intraspecific competition is
Between members of the same species competing for all the same resources they require and is therefore much
more intense that interspecific
Biotic factors are
Living e.g competition, disease, food availability, grazing, predation
Abiotic factors are
non-living, e.g. temperature, pH, light intensity, moisture
Sampling is used to
estimate the size of a population of an organism in a habitat or ecosystem.
Sampling plants and animals: techniques include
Quadrats or pitfall traps, plus transect, Tullgren funnel, pooters, tree beating, sweep net, pond netting
Equipment required to measure abiotic factors include
Light meters, moisture meters, pH meters and thermometers
All sampling and measuring techniques need to be evaluated for
Limitations and sources of error
Paired statement and branched keys can be used to
Identify organisms
Indicator species are species that
By their presence or absence indicate environmental quality/levels of pollution
e. g. lichen
e. g. freshwater invertebrates
Photosynthesis has two stages called
Light reactions and carbon fixation
Light reactions need
light energy from the sun, and water
Light energy from the sun is
trapped by chlorophyll in the chloroplasts and is converted into chemical energy and used to generate ATP
Water is
Split to produce hydrogen and oxygen.
Hydrogen
Is used in stage 2
Oxygen then
Diffuses out of the cell as a by-product
Carbon fixation needs
Hydrogen, ATP and carbon dioxide
A series of enzyme-controlled reactions produces
Sugar
The Sugar produced in photosynthesis can be used for
Respiration (glucose), making starch for storage or cellulose for structural uses.
Limiting factors are factors that
If in short supply will limit the rate of photosynthesis and plant growth
Examples of limiting factors are
CO2 concentration, light intensity and temperature
Between levels in a food chain, 90% energy is
Lost as heat, movement or undigested materials
Only a small quantity is used for
growth and is therefore available at the next level of a food chain
A pyramid of numbers is
A diagram which shows the relative total number of organisms present at each stage in the food chain.
A pyramid of energy is
a diagram which shows the total energy of organisms present at each stage in the food chain.
Unusual pyramids (non-pyramidal) of numbers exist when
The producer is a single organism (a tree)
Increasing human population requir
Increased food yield
This can include the use of
Fertilisers and pesticides
Fertilisers increase the
nutrient content of soil to improve plant growth and crop yield
Nitrates dissolved in soil water are absorbed by plants via roots and are used to make
Amino acids which are used to build Proteins
Fertilisers can leach into fresh water causing
Algal blooms
Algal blooms lead to
A reduction in light levels, killing aquatic plants
Dead plants and dead algae
Become food for bacteria, which increase greatly in number
The bacteria
Use up large quantities of oxygen, reducing availability for other organisms
Pesticides are used to
Kill plants and animals that reduce crop yield
Pesticides sprayed onto crops can
Accumulate in the bodies of organisms over time (bioaccumulation)
Pesticides are passed along food chains and
Toxicity increases and can reach lethal levels
Biological control may be
An alternative to pesticides (e.g. ladybirds controlling greenfly populations)
GM crops may be
An alternative to fertiliser use (e.g. increased yield varieties)
A mutation is
A random change to genetic material: the only source of new alleles
Mutations may be
Radiation and some chemicals
Environmental factors which increase the rate of mutation are
Radiation and some chemicals
New alleles results in increased
Variation (differences) between members of a species
Variation within a population makes it possible for a population to
Evolve over time in response to changing environmental conditions
Natural selection is also called
Survival of the fittest
Natural selection occurs when:
- More offspring are produced than the environment can sustain
- There are selection pressures
- Only the best adapted individuals (those with
selective advantage) survive and breed - They pass on their advantageous alleles and
these alleles increase in frequency within the poulation
Speciation occurs when:
- Part of a population becomes isolated by an isolation barrier
- Mutations occur in each sub-population
- natural selection follows selects for different
mutations in each group due to different
selection pressures - each sub-population evolves until they become
so genetically different that they are now two
different species. - Members from each group can no longer
interbreed to produce fertile offspring
Isolating barriers can be
Geographical, ecological or reproductive
